leaky lower unit, acts like bad clutch dog

[robot]

I am pretty sure many of you have answered some of these questions in the past, and for you patience, I applaud you. I see a lot of the same questions over and over again on these forums. enough so that the stock answer should be:
have you read the service manual? have you searched the forums for similar problems? do you have the information that is necessary that makes the free advice more useful (make/model/serial number?)


1957 35HP rje-19

50 yrs on original dog and gears.

I have no forward gear(had it, then "hit a log" phenomenon a few times), then no forward gear, reverse is fine. lower unit leaks like a sieve, so I have that to fix.

question #1
is it possible that my 'hit a log'(probably 10 times)/'now no forward gear' is related to the fact that when i drained the lower unit afterward , nothing but water came out? seems unlikely, as reverse still works

I have a donor lower unit, but the clutch dog edges are not sharp and square on that. forward and reverse gear on donor have spots of rust(not bad), but I assume emery cloth will resolve that.

I have not torn apart the current lower unit to identify the condition of the dog/gears. I probably should do that

question #2
should I use my donor clutch dog with my existing forward/reverse gears (assuming their in good shape), or is mixing/matching a bad thing. Should I also be replacing the pinion gear?

my third question is philosophical.

question #3
Do i buy a pressure tested, guaranteed lower unit from laing's for $250 or do I replace forward/reverse gears/clutch dog with my donor. I am able to do the work, but doing the work twice (and paying for new dogs/gears)when the donor's clutch dog/gears slips is not worth $250

replacing the entire lower unit is much easier, and some sort of guarantee is better than my gut instinct on the donor's long-term viability

the big problem here is not the work that is involved in replacing the lower unit innards, but is the fact that I have no test tank, and I have to trailer the boat to the lake and do all of my testing in the water, if i have issues, i pull the boat out of the water and go make changes and then repeat.

question #4
are their resources/information on building/buying a test tank at a reasonable price? surely someone has some cobbled together plans?

even if i buy a guaranteed lower unit, I'm still going to mix/match all of my spare parts to make a viable second lower unit if mix/match makes sense.


question #5.
I have a very reputable repair shop (in business since the 20's) that can fix all of my issues with this lower unit, and probably provide NOS parts. but the cost will probably be exorbitant. Is repairing the existing lower unit better than replacing it?

sorry for the lengthy post..
thanks in advance for any input.

 

[Joe Reeves]

Re: leaky lower unit, acts like bad clutch dog

I would think that it is unlikely that you've hit a log nine or ten times.... possibly maybe, but unlikely!

It would be more feasable that a leak has existed in your lower unit for some time and the resulting water within would result in excess friction upon any aluminum components, in particular the aluminum cradle that the shifter clutch dog rides upon.

This would cause the cradle to wear which in turn would lead to play in the shifter dog movement. This would cause the dog to release its engagement position within the gears, in particular (in your case) forward gear.

This would allow the shifter clutch dog lobes to slip out of the gear engagement lobes, only to jump back in at the next gear lobe position (jumping out and back into gear) which would cause a jerking action which would feel like..... similar to hitting a underwater object over and over again.

Bottom line..... Time to remove and tear down that lower unit for inspection.

 

[robot]

Re: leaky lower unit, acts like bad clutch dog

obviously I hit no logs. nothing but sugar sand where I am boating.
yeah. i know I need to tear down the current lower unit.

your response makes it sound like maybe my issue is more with my shifter lever than my clutch dog.

this is promising, as I have multiple shifter lever replacements, and I would rather replace all of the shift mechanism rather than the dogs/gears.

this would also make some sense, as I doubt the entire dog/forward gear is entirely sheared off(or rounded off enough to make it useless), as to cause my current zero forward gear engagement

I guess I should tear it apart and have a look-see.

 

[F_R]

Re: leaky lower unit, acts like bad clutch dog

What is it that makes people say "surely my clutch dog and gear is not worn out". If it has been slamming in and out, it is damaged. The slamming is also very hard on other components of the linkages and will tear that stuff up too, if it goes on long enough. Or, worn out linkages will damage the dog and gear. So which came first, the chicken or the egg? Doesn't matter. A fix requires checking everything. A patch will only guarantee quickly repeated failure.